;J74 ON THE METEOROLOGY OF IRELAND. 



110 regular progression in the amount of rain-fall throughout the 

 year, such as is observed in the phenomena of temperature or 

 humidity. In Dublin the greatest rain-fall, in the mean of the 

 eleven years, occurs in October, and the least in February ; their 

 amounts are 3 '34 and 1'74 inches respectively. At Armagh the 

 maximum is in January, and the minimum in May; and they 

 amount to 375 and 215 inches. 



The fifth and last Table gives the monthly fall of rain in the 

 year 1851, at all the meteorological stations. 



It will be seen that the greatest diversity exists in the amount 

 of rain-fall in different localities. To render this more apparent, 

 ;md to facilitate the examination of the causes which influence the 

 distribution, I have, in the following Table, given the yearly rain- 

 fall at the several stations arranged in the order of magnitude, 

 beginning with the smallest : 



TOTAL RAIN-FALL IN THE YEAR 1851, AT THE SEVERAL 

 METEOROLOGICAL STATIONS. 



20-25 inches ( Portarlington, .... 21-23 inches. 



(KiUough, ..... 23-19 

 /Dublin, ...... 26-40 



25-30 



j Donaghadee, .... 27-93 ,, 



\ Courtown, ..... 29-64 



/Kilrush, ...... 32-58 



30-35 \ Armagh, ...... 33-05 



j Killybegs, ..... 33-20 



\Dumnore, ..... 33-54 



35-^0 . j Por tsh, ..... 37-24 



( Buncrana, ..... 39-28 ,, 



40-45 jMarkree, ...... 40-31 ,.. 



( Castletownsend, . . . 42-53 



4550 ,, .... Westport, ..... 45-86 



50 60 .... Cahirciveeu, .... 59-37 



Thus, the greatest rain (at Cahirciveen) is nearly treble of the 

 least (at Portarlington). The mean rain-fall throughout Ireland, 

 in the year 1851, was 34'50 inches. 



If we assume the proportion of rain at the different stations to 

 be constant, or nearly so, the numbers of the preceding Table may 



